Make CSSParserContext be garbage collected.

third_party/WebKit/Source/core/loader/resource/CSSStyleSheetResource.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
@@ skipping 35 matching lines @@
   static CSSStyleSheetResource* createForTest(const ResourceRequest&,
                                               const String& charset);
 
   ~CSSStyleSheetResource() override;
   DECLARE_VIRTUAL_TRACE();
 
   const String sheetText(MIMETypeCheck = MIMETypeCheck::Strict) const;
 
   void didAddClient(ResourceClient*) override;
 
-  StyleSheetContents* restoreParsedStyleSheet(const CSSParserContext&);
+  StyleSheetContents* restoreParsedStyleSheet(const CSSParserContext*);
   void saveParsedStyleSheet(StyleSheetContents*);
 
   void appendData(const char* data, size_t length) override;
 
  private:
   class CSSStyleSheetResourceFactory : public ResourceFactory {
    public:
     CSSStyleSheetResourceFactory() : ResourceFactory(Resource::CSSStyleSheet) {}
 
     Resource* create(const ResourceRequest& request,
@@ skipping 23 matching lines @@
   Member<StyleSheetContents> m_parsedStyleSheetCache;
 
   bool m_didNotifyFirstData;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(CSSStyleSheet);
 
 }  // namespace blink
 
 #endif